Multilevel design of school effectiveness studies in sub-Saharan Africa

School-based improvement programs represent a core strategy in improving education because they can leverage pre-existing social and organizational structures to promote coordinated and comprehensive change across multiple facets of schooling. School-based programs are generally designed to be implemented by intact schools/districts, frequently making it infeasible or atheoretical to assign students within the same school to different conditions while ensuring study validity. Rather, studies frequently assign intact schools/districts to treatment conditions to accommodate the multilevel structure of schooling and the theory of action underlying many school-based programs. In planning such studies, effective and efficient design requires plausible values of the variance partition coefficients and the variance explained by covariates during the design stage. Using representative samples of each country, we develop empirical estimates of design parameters within and across 15 countries that are intended to inform and facilitate the efficient design of multisite cluster-randomized studies of school improvement in sub-Saharan Africa.